It is well known to provide a liquid-gas accumulator to provide a supply of hydraulic fluid at a high flow rate when the accumulator is actuated. Various types of accumulators have been used in the past such as bladder types and guided float types, some of which actuate a spring-loaded liquid inlet-outlet valve. In particular, while various guided float types have been used, such floats are guided by the housing, cages, or rods, and all have the possibility of cocking or sticking and malfunctioning.
The present invention is directed to a liquid-gas accumulator having a buoyant float which is rigidly connected to the inlet-outlet valve. This eliminates any need for stabilizing guides or walls. In addition, the present float does not "float" in the sense that it travels with the liquid level, but uses buoyancy only to open the valve and then remains submerged until the liquid is released at which time the weight of the float will close the valve. In addition, the present invention includes an additional seal to overcome the problem of gas escaping from the liquid port as the liquid level inside the accumulator nears the bottom.
The present invention is directed to a liquid-gas accumulator having a housing with a top gas port and a bottom liquid port. A gas charging valve is positioned in the top port for admission of high pressure gas. A valve is positioned in the liquid port. The valve includes a sleeve having a first end which includes a valve seat, and a valve element coacting with the seat for opening and closing the Port. Spring means yieldably urges the valve to an open position. A buoyant float is rigidly connected to the valve element for controlling the opening and closing of the valve in response to the level of liquid in the housing. The buoyant float does not require guides.
Yet a further object of the present invention is the provision of a resilient seal connected between the float and the valve element positioned to seat on the first end of the sleeve as the valve closes thereby providing a second seal. This second seal allows the gas precharge in the accumulator to be sealed without requiring a large amount of liquid to remain in the accumulator to prevent the gas from escaping.
Yet a still further object of the present invention is wherein the valve is a poppet valve and the buoyant float and the resilient seal are connected to the top of the poppet.
Yet a still further object of the present invention is wherein the resilient seal extends outwardly beyond the periphery of the poppet valve for sealing and preventing the escape of the gas precharge with a minimum of liquid.
Other and further objects, features and advantages will be apparent from the following description of a presently preferred embodiment of the invention, given for the purpose of disclosure, and taken in conjunction with the accompanying drawing.